Changes that emphasize conversations over the consumption of content reduced the amount of time people spent on the platform by 5%, and resulted in people watching fewer viral videos.

“In total, we made changes that reduced time spent on Facebook by roughly 50 million hours every day,” Zuckerberg said during today’s fourth-quarter earnings call.

Zuckerberg pledged to spend 2018 fixing the problems with the social media platform that bad actors have exploited to spread misinformation and propaganda. Facebook’s back-to-basics initiative is partly a response to that.

“In 2018, we’re focused on making sure Facebook isn’t just fun to use, but also good for people’s well-being and for society,” Zuckerberg said.

The social media giant experienced its first decline in daily active U.S. and Canadian users to 184 million, from 185 million in the prior quarter. The number of daily active users globally reached 1.4 billion, up 14% from a year ago.

Facebook beat Wall Street expectations in the fourth quarter, with $12.97 billion in revenue, up from $8.8 billion a year ago. Analysts had expected revenue of $12.55 billion.

Earnings per share were $1.44, up from $1.21 a year ago. That included a one-time charge as a result of the new tax law, which reduced earnings per share by 77 cents. Without the adjustment, Facebook would have earned $2.21, exceeding the consensus of $1.94.